1. Field of the Invention
The present invention is related to a circuit breaker to automatically terminate an electricity supply in an excessive-demand condition, and more particularly to a circuit breaker which can function even though release of a reset button is blocked.
2. Description of Related Art
For protecting electrical equipment, a circuit breaker is generally used to terminate a supply of electricity when a device connected to the supply starts to draw an excessive amount of electricity.
A conventional circuit breaker is provided with two terminals. A bimetallic strip with a movable node is formed on one of the terminals, and a reset button is attached to the bimetallic strip. In a normal state, the movable node is electrically connected with an immovable node formed on the other terminal. In an excessive-demand condition, the bimetallic strip becomes hot and deforms whereby the movable node is disconnected from the immovable node to switch off the circuit. At the same time, the reset button is pushed by the bimetallic strip to pivot upwards and protrude from a housing. Normally, the protruding reset button is simply pushed by a user whereby the circuit is completed and operation of the electrical device is resumed.
However, in a situation that the reset button is blocked by something, the bimetallic strip cannot deform and the movable node can not be disconnected from the immovable node in the excessive-demand condition and so the circuit cannot be terminated. Such a condition is of course extremely dangerous and will probably result in a fire.
Therefore, the invention provides a circuit breaker to mitigate and/or obviate the aforementioned problems.
The main objective of the present invention is to provide a circuit breaker which can terminate a circuit in an excessive-demand condition even though release of a reset-button is blocked.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.